001    /*
002     * JBoss DNA (http://www.jboss.org/dna)
003     * See the COPYRIGHT.txt file distributed with this work for information
004     * regarding copyright ownership.  Some portions may be licensed
005     * to Red Hat, Inc. under one or more contributor license agreements.
006     * See the AUTHORS.txt file in the distribution for a full listing of 
007     * individual contributors. 
008     *
009     * JBoss DNA is free software. Unless otherwise indicated, all code in JBoss DNA
010     * is licensed to you under the terms of the GNU Lesser General Public License as
011     * published by the Free Software Foundation; either version 2.1 of
012     * the License, or (at your option) any later version.
013     *
014     * JBoss DNA is distributed in the hope that it will be useful,
015     * but WITHOUT ANY WARRANTY; without even the implied warranty of
016     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
017     * Lesser General Public License for more details.
018     *
019     * You should have received a copy of the GNU Lesser General Public
020     * License along with this software; if not, write to the Free
021     * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
022     * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
023     */
024    package org.jboss.dna.sequencer.image;
025    
026    import java.io.InputStream;
027    import org.jboss.dna.graph.property.NameFactory;
028    import org.jboss.dna.graph.property.Path;
029    import org.jboss.dna.graph.property.PathFactory;
030    import org.jboss.dna.graph.sequencer.StreamSequencerContext;
031    import org.jboss.dna.graph.sequencer.SequencerOutput;
032    import org.jboss.dna.graph.sequencer.StreamSequencer;
033    
034    /**
035     * A sequencer that processes the binary content of an image file, extracts the metadata for the image, and then writes that image
036     * metadata to the repository.
037     * <p>
038     * This sequencer produces data that corresponds to the following structure:
039     * <ul>
040     * <li><strong>image:metadata</strong> node of type <code>image:metadata</code>
041     * <ul>
042     * <li><strong>jcr:mimeType</strong> - optional string property for the mime type of the image</li>
043     * <li><strong>jcr:encoding</strong> - optional string property for the encoding of the image</li>
044     * <li><strong>image:formatName</strong> - string property for the name of the format</li>
045     * <li><strong>image:width</strong> - optional integer property for the image's width in pixels</li>
046     * <li><strong>image:height</strong> - optional integer property for the image's height in pixles</li>
047     * <li><strong>image:bitsPerPixel</strong> - optional integer property for the number of bits per pixel</li>
048     * <li><strong>image:progressive</strong> - optional boolean property specifying whether the image is stored in a progressive
049     * (i.e., interlaced) form</li>
050     * <li><strong>image:numberOfImages</strong> - optional integer property for the number of images stored in the file; defaults to
051     * 1</li>
052     * <li><strong>image:physicalWidthDpi</strong> - optional integer property for the physical width of the image in dots per inch</li>
053     * <li><strong>image:physicalHeightDpi</strong> - optional integer property for the physical height of the image in dots per inch</li>
054     * <li><strong>image:physicalWidthInches</strong> - optional double property for the physical width of the image in inches</li>
055     * <li><strong>image:physicalHeightInches</strong> - optional double property for the physical height of the image in inches</li>
056     * </ul>
057     * </li>
058     * </ul>
059     * </p>
060     * <p>
061     * This structure could be extended in the future to add EXIF and IPTC metadata as child nodes. For example, EXIF metadata is
062     * structured as tags in directories, where the directories form something like namespaces, and which are used by different camera
063     * vendors to store custom metadata. This structure could be mapped with each directory (e.g. "EXIF" or "Nikon Makernote" or
064     * "IPTC") as the name of a child node, with the EXIF tags values stored as either properties or child nodes.
065     * </p>
066     * 
067     * @author Randall Hauch
068     * @author John Verhaeg
069     */
070    public class ImageMetadataSequencer implements StreamSequencer {
071    
072        public static final String METADATA_NODE = "image:metadata";
073        public static final String IMAGE_PRIMARY_TYPE = "jcr:primaryType";
074        public static final String IMAGE_MIXINS = "jcr:mixinTypes";
075        public static final String IMAGE_MIME_TYPE = "jcr:mimeType";
076        public static final String IMAGE_ENCODING = "jcr:encoding";
077        public static final String IMAGE_FORMAT_NAME = "image:formatName";
078        public static final String IMAGE_WIDTH = "image:width";
079        public static final String IMAGE_HEIGHT = "image:height";
080        public static final String IMAGE_BITS_PER_PIXEL = "image:bitsPerPixel";
081        public static final String IMAGE_PROGRESSIVE = "image:progressive";
082        public static final String IMAGE_NUMBER_OF_IMAGES = "image:numberOfImages";
083        public static final String IMAGE_PHYSICAL_WIDTH_DPI = "image:physicalWidthDpi";
084        public static final String IMAGE_PHYSICAL_HEIGHT_DPI = "image:physicalHeightDpi";
085        public static final String IMAGE_PHYSICAL_WIDTH_INCHES = "image:physicalWidthInches";
086        public static final String IMAGE_PHYSICAL_HEIGHT_INCHES = "image:physicalHeightInches";
087    
088        /**
089         * {@inheritDoc}
090         * 
091         * @see StreamSequencer#sequence(InputStream, SequencerOutput, StreamSequencerContext)
092         */
093        public void sequence( InputStream stream,
094                              SequencerOutput output,
095                              StreamSequencerContext context ) {
096    
097            ImageMetadata metadata = new ImageMetadata();
098            metadata.setInput(stream);
099            metadata.setDetermineImageNumber(true);
100            metadata.setCollectComments(true);
101    
102            // Process the image stream and extract the metadata ...
103            if (!metadata.check()) {
104                metadata = null;
105            }
106    
107            // Generate the output graph if we found useful metadata ...
108            if (metadata != null) {
109                NameFactory nameFactory = context.getValueFactories().getNameFactory();
110                PathFactory pathFactory = context.getValueFactories().getPathFactory();
111                Path metadataNode = pathFactory.create(METADATA_NODE);
112    
113                // Place the image metadata into the output map ...
114                output.setProperty(metadataNode, nameFactory.create(IMAGE_PRIMARY_TYPE), "image:metadata");
115                // output.psetProperty(metadataNode, nameFactory.create(IMAGE_MIXINS), "");
116                output.setProperty(metadataNode, nameFactory.create(IMAGE_MIME_TYPE), metadata.getMimeType());
117                // output.setProperty(metadataNode, nameFactory.create(IMAGE_ENCODING), "");
118                output.setProperty(metadataNode, nameFactory.create(IMAGE_FORMAT_NAME), metadata.getFormatName());
119                output.setProperty(metadataNode, nameFactory.create(IMAGE_WIDTH), metadata.getWidth());
120                output.setProperty(metadataNode, nameFactory.create(IMAGE_HEIGHT), metadata.getHeight());
121                output.setProperty(metadataNode, nameFactory.create(IMAGE_BITS_PER_PIXEL), metadata.getBitsPerPixel());
122                output.setProperty(metadataNode, nameFactory.create(IMAGE_PROGRESSIVE), metadata.isProgressive());
123                output.setProperty(metadataNode, nameFactory.create(IMAGE_NUMBER_OF_IMAGES), metadata.getNumberOfImages());
124                output.setProperty(metadataNode, nameFactory.create(IMAGE_PHYSICAL_WIDTH_DPI), metadata.getPhysicalWidthDpi());
125                output.setProperty(metadataNode, nameFactory.create(IMAGE_PHYSICAL_HEIGHT_DPI), metadata.getPhysicalHeightDpi());
126                output.setProperty(metadataNode, nameFactory.create(IMAGE_PHYSICAL_WIDTH_INCHES), metadata.getPhysicalWidthInch());
127                output.setProperty(metadataNode, nameFactory.create(IMAGE_PHYSICAL_HEIGHT_INCHES), metadata.getPhysicalHeightInch());
128            }
129        }
130    }